Earthquake Science最新文献

{"title":"Theories and applications of earthquake-induced gravity variation: Advances and perspectives","authors":"He Tang ,&nbsp;Wenke Sun","doi":"10.1016/j.eqs.2023.09.001","DOIUrl":"https://doi.org/10.1016/j.eqs.2023.09.001","url":null,"abstract":"<div><p>Earthquake-induced gravity variation refers to changes in the earth’s gravity field associated with seismic activities. In recent years, development in the theories has greatly promoted seismic deformation research, laying a solid theoretical foundation for the interpretation and application of seismological gravity monitoring. Traditional terrestrial gravity measurements continue to play a significant role in studies of interseismic, co-seismic, and post-seismic gravity field variations. For instance, superconducting gravimeter networks can detect co-seismic gravity change at the sub-micro Gal level. At the same time, the successful launch of satellite gravity missions (e.g., the Gravity Recovery and Climate Experiment or GRACE) has also facilitated applied studies of the gravity variation associated with large earthquakes, and several remarkable breakthroughs have been achieved. The progress in gravity observation technologies (e.g., GRACE and superconducting gravimetry) and advances in the theories have jointly promoted seismic deformation studies and raised many new research topics. For example, superconducting gravimetry has played an important role in analyses of episodic tremor, slow-slip events, and interseismic strain patterns; the monitoring of transient gravity signals and related theories have provided a new perspective on earthquake early warning systems; the mass transport detected by the GRACE satellites several months before an earthquake has brought new insights into earthquake prediction methods; the use of artificial intelligence to automatically identify tiny gravity change signals is a new approach to accurate and rapid determination of earthquake magnitude and location. Overall, many significant breakthroughs have been made in recent years, in terms of the theory, application, and observation measures. This article summarizes the progress, with the aim of providing a reference for seismologists and geodetic researchers studying the phenomenon of gravity variation, advances in related theories and applications, and future research directions in this discipline.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 5","pages":"Pages 376-415"},"PeriodicalIF":1.2,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49703135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joint inversion of Rayleigh group and phase velocities for S-wave velocity structure of the 2021 MS6.0 Luxian earthquake source area, China","authors":"Wei Xu ,&nbsp;Pingping Wu ,&nbsp;Dahu Li ,&nbsp;Huili Guo ,&nbsp;Qiyan Yang ,&nbsp;Laiyu Lu ,&nbsp;Zhifeng Ding","doi":"10.1016/j.eqs.2023.09.003","DOIUrl":"https://doi.org/10.1016/j.eqs.2023.09.003","url":null,"abstract":"<div><p>On September 16, 2021, a <em>M</em>_S6.0 earthquake struck Luxian County, one of the shale gas blocks in the Southeastern Sichuan Basin, China. To understand the seismogenic environment and its mechanism, we inverted a fine three-dimensional S-wave velocity model from ambient noise tomography using data from a newly deployed dense seismic array around the epicenter, by extracting and jointly inverting the Rayleigh phase and group velocities in the period of 1.6–7.2 s. The results showed that the velocity model varied significantly beneath different geological units. The Yujiasi syncline is characterized by low velocity at depths of ∼ 3.0–4.0 km, corresponding to the stable sedimentary layer in the Sichuan Basin. The eastern and western branches of the Huayingshan fault belt generally exhibit high velocities in the NE-SW direction, with a few local low-velocity zones. The Luxian <em>M</em>_S6.0 earthquake epicenter is located at the boundary between the high- and low-velocity zones, and the earthquake sequences expand eastward from the epicenter at depths of 3.0–5.0 km. Integrated with the velocity variations around the epicenter, distribution of aftershock sequences, and focal mechanism solution, it is speculated that the seismogenic mechanism of the main shock might be interpreted as the reactivation of pre-existing faults by hydraulic fracturing.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 5","pages":"Pages 356-375"},"PeriodicalIF":1.2,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49702931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An accessible strong-motion dataset (PGA, PGV, and site vS30) of 2022 MS6.8 Luding, China Earthquake","authors":"Jian Zhou ,&nbsp;Nan Xi ,&nbsp;Chuanchuan Kang ,&nbsp;Li Li ,&nbsp;Kun Chen ,&nbsp;Xin Tian ,&nbsp;Chao Wang ,&nbsp;Jifeng Tian","doi":"10.1016/j.eqs.2023.01.001","DOIUrl":"10.1016/j.eqs.2023.01.001","url":null,"abstract":"<div><p>A <em>M</em>_S6.8 earthquake occurred on 5th September 2022 in Luding county, Sichuan, China, at 12: 52 Beijing Time (4:52 UTC). We complied a dataset of PGA, PGV, and site <em>v</em>_S30 of 73 accelerometers and 791 Micro-Electro-Mechanical System (MEMS) sensors within 300 km of the epicenter. The inferred <em>v</em>_S30 of 820 recording sites were validated. The study results show that: (1) The maximum horizontal PGA and PGV reaches 634.1 Gal and 71.1 cm/s respectively. (2) Over 80% of records are from soil sites. (3) The <em>v</em>_S30 proxy model of Zhou J et al. is superior than that of Wald and Allen and performs well in the study area. The dataset was compiled in a flat file that consists the information of strong-motion instruments, the strong-motion records, and the <em>v</em>_S30 of the recording sites. The dataset is available at <span>https://www.seismisite.net</span><svg><path></path></svg>.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 4","pages":"Pages 309-315"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44358308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upper crustal deformation characteristics in the northeastern Tibetan Plateau and its adjacent areas revealed by GNSS and anisotropy data","authors":"Shuyu Li,&nbsp;Yuan Gao,&nbsp;Honglin Jin","doi":"10.1016/j.eqs.2023.05.003","DOIUrl":"10.1016/j.eqs.2023.05.003","url":null,"abstract":"<div><p>The northeastern part of the Tibetan Plateau is a region where different tectonic blocks collide and intersect, and large earthquakes are frequent. Global Navigation Satellite System (GNSS) observations show that tectonic deformation in this region is strong and manifests as non-uniform deformation associated with tectonic features. S-wave splitting studies of near-field seismic data show that seismic anisotropy parameters can also reveal the upper crustal medium deformation beneath the reporting station. In this paper, we summarize the surface deformation from GNSS observations and crustal deformation from seismic anisotropy data in the northeastern Tibetan Plateau. By comparing the principal compressive strain direction with the fast S-wave polarization direction of near-field S-wave splitting, we analyzed deformation and its differences in surface and upper crustal media in the northeastern Tibetan Plateau and adjacent areas. The principal compressive strain direction derived from GNSS is generally consistent with the polarization direction of fast S-waves, but there are also local tectonic regions with large differences between them, which reflect the different deformation mechanisms of regional upper crustal media. The combination of GNSS and seismic anisotropy data can reveal the depth variation characteristics of crustal deformation and deepen understanding of three-dimensional crustal deformation and the deep dynamical mechanisms underlying it. it.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 4","pages":"Pages 297-308"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46950203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid source inversions of the 2023 SE Türkiye earthquakes with teleseismic and strong-motion data","authors":"Chenyu Xu ,&nbsp;Yong Zhang ,&nbsp;Sibo Hua ,&nbsp;Xu Zhang ,&nbsp;Lisheng Xu ,&nbsp;Yuntai Chen ,&nbsp;Tuncay Taymaz","doi":"10.1016/j.eqs.2023.05.004","DOIUrl":"10.1016/j.eqs.2023.05.004","url":null,"abstract":"<div><p>We conducted rapid inversions of rupture process for the 2023 earthquake doublet occurred in SE Türkiye, the first with a magnitude of <em>M</em>_W7.8 and the second with a magnitude of <em>M</em>_W7.6, using teleseismic and strong-motion data. The teleseismic rupture models of the both events were obtained approximately 88 and 55 minutes after their occurrences, respectively. The rupture models indicated that the first event was an asymmetric bilateral event with ruptures mainly propagating to the northeast, while the second one was a unilateral event with ruptures propagating to the west. This information could be useful in locating the meizoseismal areas. Compared with teleseismic models, the strong-motion models showed relatively higher resolution. A noticeable difference was found for the <em>M</em>_W7.6 earthquake, for which the strong-motion models shows a bilateral event, rather than a unilateral event, but the dominant rupture direction is still westward. Nevertheless, all strong-motion models are consistent with the teleseismic models in terms of magnitudes, durations, and dominant rupture directions. This suggests that both teleseismic and strong-motion data can be used for fast determination of major source characteristics. In contrast, the strong-motion data would be preferable in future emergency responses since they are recorded earlier and have a better resolution ability on the source ruptures.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 4","pages":"Pages 316-327"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48420452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulse-like ground motion observed during the 6 February 2023 MW7.8 Pazarcık Earthquake (Kahramanmaraş, SE Türkiye)","authors":"Fan Wu ,&nbsp;Junju Xie ,&nbsp;Zhao An ,&nbsp;Chenghao Lyu ,&nbsp;Tuncay Taymaz ,&nbsp;Tahir Serkan Irmak ,&nbsp;Xiaojun Li ,&nbsp;Zengping Wen ,&nbsp;Baofeng Zhou","doi":"10.1016/j.eqs.2023.05.005","DOIUrl":"10.1016/j.eqs.2023.05.005","url":null,"abstract":"<div><p>In this study, we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 <em>M</em>_W7.8 Pazarcık (Kahramanmaraş) Earthquake in SE Türkiye. The wavelet method was utilized to identify and analyze the characteristics of pulse-like ground motions in the near-fault region, while considering the uncertainty of the pulse orientation during the analysis. Our investigation focused on the effects of the focal mechanism and rupture process on the spatial distribution, pulse orientation, and maximum pulse direction of the observed pulse-like ground motion. We also analyzed the amplitude and period of the observed ground pulses and the effect of long-period amplification on the ground motion response spectra. Our results indicated the following: (1) A total of 21 typical ground velocity pulses were observed during this earthquake, exhibiting complex characteristics due to the influence of the strike-slip mechanism and rupture directivity. Most ground pulses (17 out of 21) were recorded within 20 km of the fault, in a wide range of orientations, including normal and parallel to the fault direction. The waveforms exhibited unidirectional features, indicating the effects of left-lateral fault slip. Distinct pulses observed more than 20 km from the fault were mainly oriented normal to the fault. The waveforms were bidirectional with double- or multi-round trips as a result of rupture directivity. (2) The amplitudes of the observed pulses ranged from 30.5 to 220.0 cm/s, with the largest peak velocity of 220.0 cm/s observed at Station 3138. The pulse periods ranged from 2.3 to 14.5 s, with the longest pulse period of 14.5 s observed at Station 3116. The amplitude and period of the pulses observed during this earthquake were comparable to those of similar-magnitude global earthquakes. The amplitude of the pulses decreased significantly with increasing fault distance, whereas the pulse period was not significantly affected by the fault distance. (3) Compared with non-pulse records, the velocity pulse records had a pronounced amplification effect on the acceleration response spectra near the pulse period, with factors ranging from 2.1 to 5.8. The larger velocity pulses also significantly amplified the velocity response spectra, particularly over the long periods. This significant amplification effect of the pulses on the response spectra leads to empirical models underestimating the long-period earthquake ground motion.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 4","pages":"Pages 328-339"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47439082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulating the strong ground motion of the 2022 MS6.8 Luding, Sichuan, China Earthquake","authors":"Libao Zhang ,&nbsp;Lei Fu ,&nbsp;Aiwen Liu ,&nbsp;Su Chen","doi":"10.1016/j.eqs.2023.05.001","DOIUrl":"10.1016/j.eqs.2023.05.001","url":null,"abstract":"<div><p>Stochastic finite-fault simulations are effective for simulating ground motions and are widely used in engineering to determine the impacts of ground motion and develop relevant predictive equations. In this study, the source, path, and site amplification coefficient of western Sichuan Province, China, and stochastic finite-fault simulations were used to simulate the acceleration time series, Fourier amplitude spectra, and 5% damped response spectra of 28 strong-motion stations with rupture distances within 300 km of the 2022 <em>M</em>_S6.8 Luding earthquake. The simulation results of 14 stations at rupture distances of 45–185 km match the observation. However, the simulation results of 3 near- and 6 far-field stations at rupture distances of 12–36 km and 222–286 km, respectively, were obviously deviated from the observations. Simulation results of the near-field stations are larger than the observations at high frequencies (&gt;6 Hz). The discrepancy likely comes from the nonlinear site effect of near-field stations, which reduced the site amplification at high frequencies. Simulation result of the far-field stations is smaller than the observation at frequencies above 1 Hz. As these stations are located close to the Longmenshan Fault Zone (LFZ), thus, we obtained a new quality factor (<em>Q</em>) from data of historical events and stations located around LFZ. Using the new <em>Q</em> value, the discrepancies of the high-frequency simulation results of the far-field stations were corrected. This result indicated that the laterally varying <em>Q</em> values can be used to address the impact of strong crustal lateral heterogeneity on simulation.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 4","pages":"Pages 283-296"},"PeriodicalIF":1.2,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47898533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband ground motion simulation using a hybrid approach of the May 21, 2021 M7.4 earthquake in Maduo, Qinghai, China","authors":"Yijun Liu ,&nbsp;Xiaofen Zhao ,&nbsp;Zengping Wen ,&nbsp;Jie Liu ,&nbsp;Bo Chen ,&nbsp;Chunyao Bu ,&nbsp;Chao Xu","doi":"10.1016/j.eqs.2023.04.001","DOIUrl":"10.1016/j.eqs.2023.04.001","url":null,"abstract":"<div><p>In this study, the broadband ground motions of the 2021 <em>M</em>7.4 Maduo earthquake were simulated to overcome the scarcity of ground motion recordings and the low resolution of macroseismic intensity map in sparsely populated high-altitude regions. The simulation was conducted with a hybrid methodology, combining a stochastic high-frequency simulation with a low-frequency ground motion simulation, from the regional 1-D velocity structure model and the Wang WM et al. (2022) source rupture model, respectively. We found that the three-component waveforms simulated for specific stations matched the waveforms recorded at those stations, in terms of amplitude, duration, and frequency content. The validation results demonstrate the ability of the hybrid simulation method to reproduce the main characteristics of the observed ground motions for the 2021 Maduo earthquake over a broad frequency range. Our simulations suggest that the official map of macroseismic intensity tends to overestimate shaking by one intensity unit. Comparisons of simulations with empirical ground motion models indicate generally good consistency between the simulated and empirically predicted intensity measures. The high-frequency components of ground motions were found to be more prominent, while the low-frequency components were not, which is unexpected for large earthquakes. Our simulations provide valuable insight into the effects of source complexity on the level and variability of the resulting ground motions. The acceleration and velocity time histories and corresponding response spectra were provided for selected representative sites where no records were available. The simulated results have important implications for evaluating the performance of engineering structures in the epicentral regions of this earthquake and for estimating seismic hazards in the Tibetan regions where no strong ground motion records are available for large earthquakes.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 3","pages":"Pages 175-199"},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42689959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of the influencing factors on teleseismic traveltime tomography","authors":"Yang Pan ,&nbsp;Shaolin Liu ,&nbsp;Dinghui Yang ,&nbsp;Wenshuai Wang ,&nbsp;Xiwei Xu ,&nbsp;Wenhao Shen ,&nbsp;Mengyang Li","doi":"10.1016/j.eqs.2022.12.006","DOIUrl":"10.1016/j.eqs.2022.12.006","url":null,"abstract":"<div><p>Teleseismic traveltime tomography is an important tool for investigating the crust and mantle structure of the Earth. The imaging quality of teleseismic traveltime tomography is affected by many factors, such as mantle heterogeneities, source uncertainties and random noise. Many previous studies have investigated these factors separately. An integral study of these factors is absent. To provide some guidelines for teleseismic traveltime tomography, we discussed four main influencing factors: the method for measuring relative traveltime differences, the presence of mantle heterogeneities outside the imaging domain, station spacing and uncertainties in teleseismic event hypocenters. Four conclusions can be drawn based on our analysis. (1) Comparing two methods, i.e., measuring the traveltime difference between two adjacent stations (M1) and subtracting the average traveltime of all stations from the traveltime of one station (M2), reveals that both M1 and M2 can well image the main structures; while M1 is able to achieve a slightly higher resolution than M2; M2 has the advantage of imaging long wavelength structures. In practical teleseismic traveltime tomography, better tomography results can be achieved by a two-step inversion method. (2) Global mantle heterogeneities can cause large traveltime residuals (up to about 0.55 s), which leads to evident imaging artifacts. (3) The tomographic accuracy and resolution of M1 decrease with increasing station spacing when measuring the relative traveltime difference between two adjacent stations. (4) The traveltime anomalies caused by the source uncertainties are generally less than 0.2 s, and the impact of source uncertainties is negligible.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 3","pages":"Pages 228-253"},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44189294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quality influencing factors of dispersion curves from short period dense arrays based on a convolutional neural network across the north section of the Xiaojiang fault area","authors":"Si Chen ,&nbsp;Rui Gao ,&nbsp;Zhanwu Lu ,&nbsp;Yao Liang ,&nbsp;Wei Cai ,&nbsp;Lifu Cao ,&nbsp;Zilong Chen ,&nbsp;Guangwen Wang","doi":"10.1016/j.eqs.2023.04.004","DOIUrl":"10.1016/j.eqs.2023.04.004","url":null,"abstract":"<div><p>The number of dispersion curves increases significantly when the scale of a short-period dense array increases. Owing to a substantial increase in data volume, it is important to quickly evaluate dispersion curve quality as well as select the available dispersion curve. Accordingly, this study quantitatively evaluated dispersion curve quality by training a convolutional neural network model for ambient noise tomography using a short-period dense array. The model can select high-quality dispersion curves that exhibit a ≤ 10% difference between the results of manual screening and the proposed model. In addition, this study established a dispersion curve loss function by analyzing the quality of the dispersion curve and the corresponding influencing factors, thereby estimating the number of available dispersion curves for the existing observation systems. Furthermore, a Monte Carlo simulation experiment is used to illustrates the station-pair interval distance probability density function, which is independent of station number in the observational system with randomly deployed stations. The results suggested that the straight-line length should exceed 15 km to ensure that loss rate of dispersion curves remains &lt; 0.5, while maintaining the threshold ambient noise tomography accuracy within the study area.</p></div>","PeriodicalId":46333,"journal":{"name":"Earthquake Science","volume":"36 3","pages":"Pages 200-211"},"PeriodicalIF":1.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45172573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}